Field devices are, for example, used in measuring and automation engineering. In order to be prepared independently of an electricity supply by way of an electricity grid or for the case of a power outage, field devices may comprise an energy storage device that makes it possible to operate the field device independently of an electricity supply by way of an electricity grid. The term “energy storage device” may, for example, refer to rechargeable batteries.
In particular, the term “energy storage device” may refer to rechargeable batteries which during operation of the field device are charged by way of an electricity grid.